Fingerprint recognition device and a driving method thereof

ABSTRACT

A fingerprint recognition device including: a sensing panel including a plurality of sensing blocks, wherein each of the sensing blocks includes a plurality of sensors; a scan driving unit configured to provide a scan signal to the sensors; and a timing controller configured to provide a second initiation signal to the scan driving unit, wherein each of the sensors includes a reference capacitor and a sensing capacitor, the scan driving unit includes scan drivers that correspond to rows of the sensing blocks, in a fingerprint recognition mode, the timing controller provides the second initiation signal to a scan driver corresponding to a sensing block where a touch input is generated, and in a touch mode, the timing controller sequentially provides the second initiation signal to the scan drivers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of U.S. patent applicationSer. No. 16/545,180 filed on Aug. 20, 2019, which claims priority under35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0097274, filedon Aug. 21, 2018, the disclosures of which are incorporated by referenceherein in their entireties.

TECHNICAL FIELD

The present inventive concept relates to a fingerprint recognitiondevice, and more particularly, to a fingerprint recognition deviceincluding self-capacitance or optical fingerprint sensors.

DESCRIPTION OF THE RELATED ART

Computer-based systems for various purposes, such as laptop computers,tablet personal computers (PCs), smartphones, personal digitalassistants (PDAs), automated teller machines (ATMs), search guidancesystems, etc., have been developed. Since the computer-based systemsstore various confidential data such as personal information, businessinformation or trade secrets, there is the need to protect suchconfidential data. To accomplish this, fingerprint sensors have beendeveloped.

Fingerprint sensors are sensors capable of sensing human fingerprints.Fingerprint sensors may be classified as an optical fingerprint sensoror a capacitive fingerprint sensor. The optical fingerprint sensordetects a fingerprint by emitting light using a light source such as alight-emitting diode (LED) and sensing light reflected from the ridgesand valleys of a finger via a complementary metal-oxide-semiconductor(CMOS) image sensor. The capacitive fingerprint sensor detects afingerprint by using a capacitance generated between the capacitivefingerprint sensor and a ridge or a valley of a finger in contact withthe capacitive fingerprint sensor.

SUMMARY

According to an exemplary embodiment of the present inventive concept, afingerprint recognition device comprises a sensing panel including aplurality of sensing blocks, wherein each of the sensing blocks includesa plurality of sensors; a scan driving unit configured to provide a scansignal to the sensors; and a timing controller configured to provide asecond initiation signal to the scan driving unit, wherein each of thesensors includes a reference capacitor and a sensing capacitor, the scandriving unit includes scan drivers that correspond to rows of thesensing blocks, in a fingerprint recognition mode, the timing controllerprovides the second initiation signal to a scan driver corresponding toa sensing block where a touch input is generated, and in a touch mode,the timing controller sequentially provides the second initiation signalto the scan drivers.

The reference capacitor may have a fixed capacitance, and the sensingcapacitor may have a variable capacitance that varies depending on adistance to a fingerprint.

The fingerprint recognition device may further comprise an emissiondriving unit configured to receive a first initiation signal from thetiming controller and provide an emission signal to the sensors.

In the touch mode, the timing controller may provide an on-state modesignal to the scan driving unit, and in the fingerprint recognitionmode, the timing controller may provide an off-state mode signal to thescan driving unit.

In the fingerprint recognition mode, the emission driving unitsequentially may provide the emission signal to the sensors, and thescan driving unit sequentially may provide the scan signal to thesensors.

The first initiation signal may be provided before the second initiationsignal, and the emission signal may be provided before the scan signal.

The first initiation signal may include at least three consecutivepulses, and the second initiation signal may be provided when a lastpulse of the first initiation signal is provided.

In the touch mode, the emission driving unit and the scan driving unitmay provide the emission signal and the scan signal to the sensors atthe same time.

The emission driving unit and the scan driving unit may provide theemission signal and the scan signal only to some of the sensors.

The timing controller may provide first and second emission clocksignals having opposite phases with respect to each other to the scandriving unit and provides first and second scan clock signals havingopposite phases with respect to each other to the scan driving unit, thefirst and second emission clock signals include sections modulated intohigh frequencies, and the first and second scan clock signals includesections modulated into high frequencies.

The timing controller may provide an enable signal to the emissiondriving unit and the scan driving unit, and when the enable signal isturned off, all operations of the emission driving unit and the scandriving unit may be terminated.

According to another exemplary embodiment of the present inventiveconcept, a fingerprint recognition device comprises a sensing panelincluding a plurality of sensing blocks, wherein each of the sensingblocks includes a plurality of sensors; a scan driving unit configuredto provide a scan signal to the sensors; and a timing controllerconfigured to provide an initiation signal to the scan driving unit,wherein each of the sensors includes a photoelectric conversion element,the scan driving unit includes scan drivers that correspond to rows ofthe sensing blocks, in a first mode, the timing controller sequentiallyprovides the initiation signal to the scan drivers, and in a secondmode, the timing controller provides the initiation signal to a scandriver corresponding to a sensing block where touch input is generated.

In the second mode, the scan driving unit may receive the initiationsignal and may sequentially provide the scan signal to the sensors.

The timing controller may receive a touch signal from a touch sensingunit, may detect touch coordinates from the touch signal, and mayprovide the initiation signal only to a scan driver corresponding to asensing block that corresponds to the detected touch coordinates.

The touch sensing unit may be disposed on a display panel, and thesensing panel may be attached to a bottom of the display panel.

The timing controller may provide the initiation signal to at least onescan driver adjacent to the scan driver corresponding to the sensingblock that corresponds to the detected touch coordinates.

In the first mode, the scan driving unit may provide the scan signal tothe sensors at the same time.

According to another exemplary embodiment of the present inventiveconcept a driving method of a fingerprint recognition device comprisinga sensing panel including a plurality of sensing blocks each including aplurality of sensors, an emission driving unit for providing an emissionsignal to the sensors, a scan driving unit for providing a scan signalto the sensors, and a timing controller for providing a first initiationsignal to the emission driving unit and for providing a secondinitiation signal to the scan driving unit, the driving method comprisesreceiving a touch input at the sensing panel; determining, by the timingcontroller, whether a mode signal is on or off; and driving thefingerprint recognition device in a fingerprint recognition mode whenthe mode signal is off and driving the fingerprint recognition device ina touch mode when the mode signal is on.

The driving of the fingerprint recognition device in the fingerprintrecognition mode, comprises sequentially providing, by the timingcontroller, the first initiation signal to the emission driving unit,sequentially providing, by the emission driving unit, the emissionsignal to the sensors, providing, by the timing controller, the secondinitiation signal to the scan driving unit, sequentially providing, bythe scan driving unit, the scan signal to the sensors, and turning off,by the timing controller, an enable signal, and the first and secondinitiation signals may be provided to an emission driver and a scandriver both corresponding to a row including a sensing block where thetouch input is generated.

The driving of the fingerprint recognition device in the touch mode,comprises turning on, by the timing controller, the enable signal,providing, by the timing controller, the first and second initiationsignals to the scan driving unit and the emission driving unit at thesame time, providing, by the emission driving unit and the scan drivingunit, the emission signal and the scan signal to the sensors at the sametime, and turning off, by the timing controller, the enable signal, andthe first and second initiation signals may be sequentially provided toemission drivers that are disposed to correspond to rows of the sensingblocks and to scan drivers that are also disposed to correspond to therows of the sensing blocks.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present inventive concept willbecome more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings, in which:

FIG. 1 is a block diagram of a display device according to an exemplaryembodiment of the present inventive concept;

FIG. 2 is a block diagram of a fingerprint recognition device accordingto an exemplary embodiment of the present inventive concept;

FIG. 3 is an enlarged view of an area A of FIG. 2;

FIG. 4 is a circuit diagram of a capacitive fingerprint sensor accordingto an exemplary embodiment of the present inventive concept;

FIGS. 5A and 5B are schematic views illustrating how a line-drivingfingerprint recognition method differs from an area-driving fingerprintrecognition method;

FIG. 6 is a waveform diagram showing emission clock signals and scanclock signals according to an exemplary embodiment of the presentinventive concept;

FIG. 7 is a block diagram illustrating signal flows in the fingerprintrecognition device according to an exemplary embodiment of the presentinventive concept;

FIG. 8 is a flowchart illustrating the operation of the fingerprintrecognition device according to an exemplary embodiment of the presentinventive concept;

FIG. 9 is a timing diagram showing signals output by a timing controllerand a sensing driver of the fingerprint recognition device according toan exemplary embodiment of the present inventive concept in afingerprint recognition mode;

FIG. 10 is a timing diagram showing signals output by the timingcontroller and the sensing driver of the fingerprint recognition deviceaccording to an exemplary embodiment of the present inventive conceptwhen the fingerprint recognition mode is complete;

FIG. 11 is a timing diagram showing signals output by the timingcontroller and the sensing driver of the fingerprint recognition deviceaccording to an exemplary embodiment of the present inventive conceptwhen a touch mode is driven and when the touch mode is complete;

FIG. 12 is a circuit diagram of a capacitive fingerprint sensoraccording to another exemplary embodiment of the present inventiveconcept;

FIG. 13 is a circuit diagram of an optical fingerprint sensor accordingto an exemplary embodiment of the present inventive concept;

FIG. 14 is a block diagram of a display device including the fingerprintsensor of FIG. 13;

FIG. 15 is a block diagram of a fingerprint recognition device includingthe optical fingerprint sensor of FIG. 13; and

FIG. 16 is a circuit diagram of an optical fingerprint sensor accordingto another exemplary embodiment of the present inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present inventive concept will be describedmore fully hereinafter with reference to the accompanying drawings. Thepresent inventive concept may, however, be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present.

In the drawings, components may be exaggerated or reduced in size forconvenience of explanation.

Throughout the specification, like reference numerals may refer to likeelements.

FIG. 1 is a block diagram of a display device according to an exemplaryembodiment of the present inventive concept. FIG. 2 is a block diagramof a fingerprint recognition device according to an exemplary embodimentof the present inventive concept. FIG. 3 is an enlarged view of an areaA of FIG. 2.

Referring to FIGS. 1 through 3, a display device 10 may include adisplay panel 100, a data driving unit 110, a gate driving unit 120, asensing panel 205, a sensing driving unit 215, a read-out circuit unit230, and a timing controller 300. A fingerprint recognition device 200may include the sensing panel 205, the sensing driving unit 215, theread-out circuit unit 230, and the timing controller 300. The sensingdriving unit 215 may include a scan driving unit 210 and an emissiondriving unit 220. The timing controller 300 may provide various controlsignals to the display panel 100 and the fingerprint recognition device200.

The display panel 100 may include a plurality of pixels PX and mayprovide an image to the outside. The display panel 100 may be an organiclight-emitting diode (OLED) display panel including OLEDs. In thedescription that follows, it is assumed that the display panel 100 is anOLED display panel, but the present inventive concept is not limitedthereto. Alternatively, the display panel 100 may be a liquid crystaldisplay (LCD) panel or a micro light-emitting diode (mLED) displaypanel.

In the display panel 100, data lines DL1 through DLm (where m is apositive integer of 2 or greater) and gate lines GL1 through GLn (wheren is a positive integer of 2 or greater) may be disposed. The data linesDL1 through DLm and the gate lines GL1 through GLn may intersect oneanother. Each of the pixels PX of the display panel 100 may be connectedto one of the data lines DL1 through DLm and one of the gate lines GL1through GLn. Each of the pixels PX may include a driving transistor, aswitching transistor, which is controlled by a gate signal from one ofthe gate lines GL1 through GLn, a light-emitting element, and acapacitor. The driving transistor and the switching transistor may bethin-film transistors (TFTs).

The data driving unit 110 is connected to the data lines DL1 through DLmand provides data voltages to the pixels PX. The data driving unit 110may receive digital video data DATA′ and a data control signal DCS fromthe timing controller 300. The data driving unit 110 may convert thedigital video data DATA′ into data voltages in accordance with the datacontrol signal DCS and may provide the data voltages to the data linesDL1 through DLm.

The gate driving unit 120 is connected to the gate lines GL1 through GLnand provides gate voltages to the pixels PX. The gate driving unit 120may receive a gate control signal GCS from the timing controller 300.The gate driving unit 120 may sequentially provide gate voltages to thegate lines GL1 through GLn in accordance with the gate control signalGCS.

The timing controller 300 receives multiple image signals DATA andmultiple control signals CS from outside the display device 10. Thetiming controller 300 may generate image signals DATA′ (also referred toas digital video data) by converting the data format of the imagesignals DATA to be compatible with the interface specification of thedata driving unit 110 and may provide the image signals DATA′ to thedata driving unit 110. The timing controller 300 may provide the datacontrol signal DCS to the data driving unit 110.

The timing controller 300 may provide various control signals to variousdriving units. For example, the timing controller 300 may generate thegate control signal GCS and provide the gate control signal GCS to thegate driving unit 120. In addition, the timing controller 300 maygenerate a scan control signal SCS and an emission control signal ECS,provide the scan control signal SCS to the scan driving unit 210, andprovide the emission control signal ECS to the emission driving unit220. For example, the timing controller 300 may generate a read-outcontrol signal RCS, provide the read-out control signal RCS to theread-out circuit unit 230, and receive fingerprint sensing signals SSfrom the read-out circuit unit 230.

The fingerprint recognition device 200 may include the sensing panel205, the sensing driving unit 215, the read-out circuit unit 230, andthe timing controller 300.

The sensing panel 205 may include a plurality of sensors SN. The sensorsSN may be fingerprint sensors for performing a fingerprint recognitionoperation. The fingerprint sensors may be capacitive fingerprint sensorsor optical fingerprint sensors, but the present inventive concept is notlimited thereto. Alternatively, the fingerprint sensors may beultrasonic fingerprint sensors or infrared fingerprint sensors. In acase where the sensors SN are capacitive fingerprint sensors, thesensors SN may detect a fingerprint using the difference in the amountof an electrical charge between the sensors SN and ridges and valleys ofa finger that are in contact with the sensors SN. In a case where thesensors SN are optical fingerprint sensors, the sensors SN may detect afingerprint by applying light with light sources (such as light-emittingdiodes (LEDs)) provided therein and detecting light reflected fromridges and valleys of a finger with complementarymetal-oxide-semiconductor (CMOS) image sensors. In the description thatfollows, it is assumed that the sensors SN are self-capacitivefingerprint sensors. A display sensor having optical fingerprint sensorswill be described later with reference to FIGS. 13 through 15.

In the sensing panel 205, a plurality of scan lines (SL1 through SLiwhere i is a positive integer of 2 or greater), a plurality of emissionlines (EL1 through ELi where i is a positive integer of 2 or greater),and a plurality of read-out lines (RL1 through RLj where j is a positiveinteger of 2 or greater) may be disposed. The scan lines (SL1 throughSLi) and the emission lines (EL1 through ELi) may be disposed inparallel to one another. The read-out lines (RL1 through RLj) may bedisposed to intersect the scan lines (SL1 through SLi) and the emissionlines (EL1 through ELi). Each of the sensors SN of the sensing panel 205may be connected to one of the scan lines (SL1 through SLi), one of theemission lines (EL1 through ELi), and one of the read-out lines (RL1through RLj). Each of the sensors SN may include a plurality ofswitching transistors and a capacitor, which are controlled by a scansignal from one of the scan lines (SL1 through SLi) and an emissionsignal from one of the emission lines (EL1 through ELi). The switchingtransistors of each of the sensors SN may be TFTs.

The sensing driving unit 215 may include the scan driving unit 210 andthe emission driving unit 220. The sensing driving unit 215 may receivesensing control signals from the timing controller 300 and maysequentially provide a scan signal and an emission signal to the sensingpanel 205 based on the sensing control signals. The sensing controlsignals may include the scan control signal SCS and the emission controlsignal ECS.

The scan driving unit 210 is connected to the scan lines (SL1 throughSLi) and provides a scan signal to the sensors SN of the sensing panel205. The scan driving unit 210 may receive the scan control signal SCSfrom the timing controller 300. The scan control signal SCS may includea second initiation signal FLM and may control the scan driving unit210. The scan driving unit 210 may sequentially provide a scan signal tothe scan lines (SL1 through SLi) in accordance with the scan controlsignal SCS.

The emission driving unit 220 is connected to the emission lines (EL1through ELi) and provides an emission signal to the sensors SN of thesensing panel 205. The emission driving unit 220 may receive theemission control signal ECS from the timing controller 300. The emissioncontrol signal ECS may include a first initiation signal EM_FLM and maycontrol the emission driving unit 220. The emission driving unit 220 maysequentially provide an emission signal to the emission lines (EL1through ELi) in accordance with the emission control signal ECS.

The scan driving unit 210 and the emission driving unit 220 may beformed on the sensing panel 205 in agate driver-in-panel (GIP) manner.The scan driving unit 210 and the emission driving unit 220 may bedisposed on one side of the sensing panel 205. Alternatively, one pairof the scan driving unit 210 and the emission driving unit 220 may bedisposed on one side of the sensing panel 205, and another pair of thescan driving unit 210 and the emission driving unit 220 may be disposedon the other side of the sensing panel 205. In yet another alternative,the scan driving unit 210 may be disposed on one side of the sensingpanel 205, and the emission driving unit 220 may be disposed on theother side of the sensing panel 205.

The read-out circuit unit 230 may sequentially provide the fingerprintsensing signals SS, received from the read-out lines (RL1 through RLj),to the timing controller 300 in response to the read-out control signalRCS received from the timing controller 300. The timing controller 300may create a fingerprint image based on the times when a scan signal andan emission signal are generated and based on the fingerprint sensingsignals SS received from the read-out circuit unit 230. The read-outcircuit unit 230 may be disposed on the opposite side of the sensingpanel 205 with respect to the scan driving unit 210 and the emissiondriving unit 220.

For convenience, FIG. 2 illustrates some of the scan lines (SL1 throughSLi), some of the emission lines (EL1 through ELi), and some of theread-out lines (RL1 through RLj). The sensing panel 205 may include, andmay be divided into, a plurality of sensing blocks SB (SB[1,1] throughSB[i,j] where i and j are positive integers of 2 or greater). Thesensing blocks SB may be arranged in rows and columns, and the locationsof the sensing blocks SB may be represented in rows and columns. Forexample, an i-th row, j-th column sensing block SB may be represented asSB[i,j].

Each of the sensing blocks SB may include multiple sensors SN. Thesensing blocks SB may have a size compatible with the touch system ofthe display device 10. For example, the sensing blocks SB may have asquare shape having a length of 4 mm in a first direction d1 and alength of 4 mm in a second direction d2. The size of the sensing blocksSB is not particularly limited, but may vary as necessary. The number ofsensors SN provided in each of the sensing blocks SB may vary dependingon the size of the sensing blocks SB. The fingerprint recognition device200 may control a particular number of sensing blocks SB via the timingcontroller 300. For example, in a case where two rows of sensing blocksSB are driven for fingerprint recognition depending on the location of atouch input, an 8-mm long fingerprint recognition area can be secured.In another example, in a case where three rows of sensing blocks SB aredriven for fingerprint recognition, a 12-mm long fingerprint recognitionarea can be secured. The number of sensing blocks SB that are driven forsecuring a fingerprint recognition area is not particularly limited. Inother words, only one row of sensing blocks SB or four or more rows ofsensing blocks SB can be driven as necessary.

The scan lines (SL1 through SLi), the emission lines (EL1 through ELi),and the read-out lines (RL1 through RLj), which are connected to thesensors SN included in each of the sensing blocks SB, may be disposed onthe sensing blocks SB.

The scan lines (SL1 through SLi) may include first through i-th row scanlines SL1 through SLi. The first through i-th row scan lines SL1 throughSLi may be connected to first through i-th rows of sensing blocks SB.For example, the first scan line SL may be connected to the first row ofsensing blocks SB, e.g., sensing blocks SB[1,1] through SB[1,j] (where jis a positive integer of 2 or greater).

Each of the scan lines (SL1 through SLi) is illustrated as a single lineconnected to one of the sensing blocks SB. However, each of the scanlines (SL1 through SLi) may be a group of lines individually connectedto the sensors SN of one of the sensing blocks SB. Similarly, each ofthe emission lines (EL1 through ELi) and the read-out lines (RL1 throughRLj) is illustrated as a single line connected to one of the sensingblocks SB, but may be a group of lines individually connected to thesensors SN of one of the sensing blocks SB. The scan lines (SL1 throughSLi), the emission lines (EL1 through ELi), and the read-out lines (RL1through RLj) will be described later with reference to FIG. 3.

The emission lines (EL1 through ELi) may include first through i-th rowemission lines EL1 through ELi. The emission lines (EL1 through ELi) maybe connected to the sensing blocks SB in the same manner as the scanlines (SL1 through SLi).

As mentioned above, the sensing driving unit 215 may include the scandriving unit 210 and the emission driving unit 220 and may providesignals for sensing to the sensors SN of the sensing panel 205. The scandriving unit 210 may sequentially provide a scan signal to the sensingblocks SB via the scan lines (SL1 through SLi). The emission drivingunit 220 may sequentially provide an emission signal to the sensingblocks SB via the emission lines (EL1 through ELi).

The scan driving unit 210 may include scan drivers that are spaced apartfrom one another and are disposed to correspond to the rows of sensingblocks SB. In other words, scan drivers corresponding to different rowsof sensing blocks SB may be isolated from one another, and no carrysignal may exist between the scan drivers corresponding to the differentrows of sensing blocks SB. For example, in a case where a k-th row scandriver 210 k receives a k-th row second initiation signal FLMk andprovides a scan signal to a k-th row of sensors SN, no carry signal maybe transmitted to a (k+1)-th row scan driver 210 k+1. In other words,the (k+1)-th row scan driver 210 k+1 can be driven only if a (k+1)-throw second initiation signal FLMk+1 is received from the timingcontroller 300.

The emission driving unit 220, which is disposed on one side of thesensing blocks SB, may include emission drivers that are driven insuccession. In other words, the emission drivers of the emission drivingunit 220 may be connected to one another via a carry signal. Forexample, in a case where a k-th row emission driver 220 k receives ak-th row first initiation signal EM_FLMk and provides an emission signalto the k-th row of sensors SN, the k-th row emission driver 220 k maystop operating and may transmit a carry signal to a (k+1)-th rowemission driver 220 k+1 so that the (k+1)-th row emission driver 220 k+1can provide the emission signal to a (k+1)-th row of sensors SN.

The read-out lines (RL1 through RLj) may include first through j-thcolumn read-out lines RL1 through RLj. The first through j-th columnread-out lines RL1 through RLj may be connected to first through j-thcolumns of sensing blocks SB. For example, the first read-out line RL1may be connected to the first column of sensing blocks SB, e.g., thesensing blocks SB[1,1] through SB[j,1] (where j is a positive integer of2 or greater).

The area A is an area including a sensing block SB[k,1], which is in anarbitrary k-th row and the first column of the array of sensing blocksSB. In other words, the area A may include the sensing block SB[k,], ak-th row scan line SUk, and a k-th row emission line ELk. The sensingblocks SB, e.g., the sensing blocks SB[1,1] through SB[i,j], may allhave the same structure. The structure of the sensing blocks SB willhereinafter be described taking the sensing block SB[k,1] as an example.

FIG. 3 shows a plurality of sensors SN[1,1] through SN[25,40], which aredisposed in the sensing block SB[k,1], and the k-th row scan driver 210k, the k-th row emission driver 220 k, the read-out circuit unit 230,and a power supply unit 240, which are connected to the sensors SN[1,1]through SN[25,40].

Multiple sensors SN may be disposed in one sensing block SB. 25 rows and40 columns of sensors SN, e.g., a total of 1000 sensors SN, may bedisposed in the sensing block SB[k,1] of FIG. 3. However, the number andthe arrangement of sensors SN in the sensing block SB[k,1] are notparticularly limited. For example, the greater the size of the sensingblocks SB, the greater the number of sensors SN arranged in each of thesensing blocks SB.

Referring to FIG. 3, the sensors SN of the sensing block SB[k,1] may beconnected to a plurality of k-th row emission lines (EL[1] throughEL[25]), a plurality of k-th row scan lines (SL[1] through SL[25]), afirst voltage line VCL, a second voltage line VRL, and a plurality ofread-out lines (RL[1] through RL[40]).

The k-th row emission lines (EL[1] through EL[25]) may include firstthrough twenty fifth k-th row emission lines EL[1] through EL[25]. Thefirst through twenty fifth k-th row emission lines EL[1] through EL[25]may be connected to first through twenty fifth rows, respectively, ofsensors SN of the sensing block SB[k,1]. The k-th row scan lines (SL[1]through SL[25]) may include first through twenty fifth k-th row scanlines SL[1] through SL[25]. The first through twenty fifth k-th row scanlines SL[1] through SL[25] may be connected to the first through twentyfifth rows, respectively, of sensors SN of the sensing block SB[k,1].

The k-th row emission lines (EL[1] through EL[25]) and the k-th row scanlines (SL[1] through SL[25]) may be disposed in parallel to one anotherand may be connected to a k-th row of sensors SN of the sensing blockSB[k,1].

The k-th row emission driver 220 k may be disposed to correspond to thesensing block SB[k,1]. The emission drivers of the emission driving unit220 may be connected to one another. For example, the k-th row emissiondriver 220 k may start operating by receiving a carry signal from a(k−1)−th row emission driver 220 k−1 corresponding to a (k−1)-th rowsensing block SB previous to the sensing block SB[k,1]. For example, the(k+1)-th row emission driver 220 k+1 corresponding to a (k+1)-th rowsensing block SB subsequent to the sensing block SB[k,1] may startoperating by receiving a carry signal from the k-th row emission driver220 k. In other words, the emission drivers of the emission driving unit220 may be connected to one another via a carry signal. The k-th rowemission driver 220 k may start operating by receiving a carry signalfrom the (k−1)-th row emission driver 220 k-1 or by receiving the k-throw first initiation signal EM_FLMk.

The k-th row scan driver 210 k may be disposed to correspond to thesensing block SB[k,1]. The scan driving unit 210, which is disposed tocorrespond to the rows of sensing blocks SB, may be divided into blocksthat are isolated from one another. For example, the k-th row scandriver 210 k may be disposed to be isolated from the (k−1)-th rowsensing block SB previous to the sensing block SB[k,1] and from the(k+1)-th row sensing block SB subsequent to the sensing block SB[k,1].In other words, the scan drivers of the scan driving unit 210 do nottransmit a carry signal to one another and can thus be isolated from oneanother. The k-th row scan driver 210 k may start operating by receivingthe k-th row second initiation signal FLMk.

The power supply unit 240 may supply power to the sensors SN of thesensing panel 205 via the first and second voltage lines VCL and VRL.The first voltage line VCL may be a line for supplying a common voltageto the transistors included in each of the sensors SN. The secondvoltage line VRL may be a line for supplying an initialization voltageto initialize the transistors included in each of the sensors SN.

FIG. 4 is a circuit diagram of a capacitive fingerprint sensor accordingto an exemplary embodiment of the present inventive concept. The sensorsSN of the sensing panel 205 may have the same structure. Thus, thestructure of the sensors SN will hereinafter be described with referenceto FIG. 4. The configuration of FIG. 4 may refer to one pixel. Forconvenience, FIG. 4 illustrates an arbitrary sensor SN connected to anarbitrary scan line SL, an arbitrary emission line EL, an arbitraryread-out line RL, the first voltage line VCL, and the second voltageline VRL.

The scan line SL may provide a scan signal SC to the sensor SN, and theemission line EL may provide an emission signal VI to the sensor SN. Theemission signal VI may be an initialization signal. The first voltageline VCL may provide a common voltage, and the second voltage line VRLmay provide an initialization voltage.

Referring to FIG. 4, the sensor SN may include a first transistor T1, asecond transistor T2, a third transistor T3, a reference capacitor CR,and a sensing capacitor CF.

The first transistor T1 may include a first gate electrode electricallyconnected to a first node N1, a first electrode electrically connectedto the first voltage line VCL, and a second electrode electricallyconnected to a third electrode of the second transistor T2. The firsttransistor T1 may control a drain-source current Ids in accordance withthe voltage at the first node N1. The drain-source current Ids, whichflows through the channel of the first transistor T1, may beproportional to the square of the difference between a gate-sourcevoltage Vgs and a threshold voltage Vth of the first transistor T1, asshown in Equation (1):

Ids=k′×(Vgs−Vth)².

The drain-source current Ids, which varies in accordance with thevoltage at the first node N1 or a voltage caused by the drain-sourcecurrent Ids, may be a fingerprint sensing signal SS.

The second transistor T2 may include a second gate electrodeelectrically connected to the scan line SL, the third electrodeelectrically connected to the second electrode of the first transistorT1, and a fourth electrode electrically connected to the read-out lineRL. The second transistor T2 is turned on by the scan signal SC from thescan line SL to connect the first electrode of the first transistor T1and the read-out line RL. A gate-low voltage may be supplied to the scanline SL to which the second gate electrode of the second transistor T2is connected. Thus, the second transistor T2 may normally be off. Inresponse to a gate-high voltage being supplied via the scan line SL, thesecond transistor T2 may be turned on. When the second transistor T2 isturned on, a fingerprint sensing signal SS may be provided to theread-out line RL.

The third transistor T3 may include a third gate electrode electricallyconnected to the emission line EL, a fifth electrode electricallyconnected to the first node N1, and a sixth electrode electricallyconnected to the second voltage line VRL. The third transistor T3 isturned on by the emission signal VI from the emission line EL to connectthe first node N1 and the second voltage line VRL. When the thirdtransistor T3 is turned on, the first node N1 may be initialized by theinitialization voltage from the second voltage line VRL. The gate-highvoltage may be provided to the emission line EL to which the third gateelectrode of the third transistor T3 is connected. Thus, the thirdtransistor T3 may normally be on. In response to the gate-low voltagebeing provided via the emission line EL, the third transistor T3 may beturned off. In other words, when the third transistor T3 is turned offby the gate-low voltage, the first node N1 and the second voltage lineVRL may be disconnected from each other, and the voltage at the firstnode N1 may be fixed.

The reference capacitor CR may include a seventh electrode electricallyconnected to the emission line EL and an eighth electrode electricallyconnected to the first node N. The capacitance of the referencecapacitor CR may be fixed and uniform.

The sensing capacitor CF may be a capacitance generated between theridges or valleys of a finger of a user and the sensor SN. In otherwords, when there is no touch input from the user, the sensing capacitorCF does not exist. For example, only when touch input is generated bythe user, the sensing capacitor CF is generated. The sensing capacitorCF may include a ninth electrode electrically connected to the firstnode N1 and a tenth electrode connected to the body of the user. Thetenth electrode may be a ground electrode. The capacitance of thesensing capacitor CF may vary depending on the distance between thesensor SN and a fingerprint ridge or valley.

As the capacitance of the sensing capacitor CF varies, the voltage atthe first node N1 between the reference capacitor CR and the sensingcapacitor CF may vary. For example, a variation in the voltage at thefirst node N1 may be determined according to the voltage distributionlaw. In other words, when the sensing capacitor CF does not exist, thevoltage at the first node N1 may be the voltage initialized by thesecond voltage line VRL. Then, when the sensing capacitor CF isgenerated, the voltage at the first node N1 may change according to thecapacitance of the sensing capacitor CF. As mentioned above, thedrain-source current Ids of the first transistor T1 may be proportionalto the square of the difference between the gate-source voltage and thethreshold voltage of the first transistor T1. Thus, when the voltage atthe first node N1 changes, the voltage applied to the first gateelectrode of the first transistor T1 changes, and the drain-sourcecurrent Ids may also change. Accordingly, the value of the fingerprintsensing signal SS provided to the read-out line RL may change, and afingerprint can be imaged based on a variation in the value of thefingerprint sensing signal SS.

Semiconductor layers of the first, second, and third transistors T1, T2,and T3 may be formed of polysilicon, amorphous silicon, or an oxidesemiconductor. In a case where the semiconductor layers of the first,second, and third transistors T1, T2, and T3 are formed of polysilicon,the semiconductor layers of the first, second, and third transistors T1,T2, and T3 may be formed by a low-temperature polysilicon (LTPS)process.

FIG. 4 illustrates the first, second, and third transistors T1, T2, andT3 as being N-type metal oxide semiconductor field effect transistors(MOSFETs), but the present inventive concept is not limited thereto.Alternatively, the first, second, and third transistors T1, T2, and T3may be CMOS transistors or N-channel metal oxide semiconductor (NMOS)transistors. A fingerprint sensor including P-type MOSFETs will bedescribed later with reference to FIG. 12.

FIGS. 5A and 5B are schematic views illustrating how a line-drivingmethod differs from an area-driving fingerprint recognition method.FIGS. 5A and 5B illustrate sensors (SNL1, SNL2, SNL3, SNA1, SNA2, SNA3,SNA4, and SNA5) for sensing a fingerprint. FIG. 5A illustrates theline-driving fingerprint sensing method, and FIG. 5B illustrates thearea-driving fingerprint recognition method. FIGS. 5A and 5B arelongitudinal sectional views of a line-driving fingerprint recognitiondevice and an area-driving fingerprint recognition device, respectively.In other words, the sensors of FIG. 5A or 5B may all belong to differentrows.

Referring to FIG. 5A, the line driving fingerprint recognition devicemay include first, second, and third line sensors SNL1, SNL2, and SNL3.A scan signal and then an emission signal may be sequentially providedto the first, second, and third line sensors SNL1, SNL2, and SNL3 alonga sensing direction d.

Referring to FIG. 5B, the area-driving fingerprint recognition devicemay include first, second, third, fourth, and fifth area sensors SNA1,SNA2, SNA3, SNA4, and SNA5. A scan signal may be sequentially providedto the first, second, third, fourth, and fifth area sensors SNA1, SNA2,SNA3, SNA4, and SNA5 along a sensing direction d.

An emission signal may be simultaneously provided to the first, second,third, fourth, and fifth area sensors SNA1, SNA2, SNA3, SNA4, and SNA5.In other words, the emission signal may be simultaneously applied to asensor to which a scan signal is applied and to sensors adjacent to thesensor to which the scan signal is applied.

For example, three emission signals may be simultaneously provided for asingle scan signal. A fingerprint recognition device in which a scansignal is sequentially applied to the second, third, and fourth areasensors SNA2, SNA3, and SNA4 will hereinafter be described.

First, in the case of sensing a fingerprint by providing a scan signalto the second area sensor SNA2, three emission signals may besimultaneously provided to the first, second, and third area sensorsSNA1, SNA2, and SNA3. Thereafter, in the case of sensing a fingerprintby providing a scan signal to the third area sensor SNA3, three emissionsignals may be simultaneously provided to the second, third, and fourtharea sensors SNA2, SNA3, and SNA4. Finally, in the case of sensing afingerprint by providing a scan signal to the fourth area sensor SNA4,three emission signals may be simultaneously provided to the third,fourth, and fifth area sensors SNA3, SNA4, and SNA5.

In the case of sensing a fingerprint using the line-driving fingerprintrecognition method, the capacitance of a line sensing capacitor CF_L maynot be precisely measured. For example, referring to FIG. 5A, inresponse to a scan signal and an emission signal provided to the secondline sensor SNL2, the second line sensor SNL2 measures the capacitanceof the line sensing capacitor CF_L with respect to a correspondingfingerprint ridge. The line sensing capacitor CF_L may be affected by ablur phenomenon between the fingerprint ridge corresponding to thesecond line sensor SNL2 and a fingerprint valley adjacent to thefingerprint ridge corresponding to the second line sensor SNL2. Forexample, the distance from the second line sensor SNL2 to thefingerprint valley adjacent to the fingerprint ridge corresponding tothe second line sensor SNL2 may be greater than the distance from thesecond line sensor SNL2 to the fingerprint ridge corresponding to thesecond line sensor SNL2. In other words, the average distance betweenthe second line sensor SNL2 and the fingerprint ridge corresponding tothe second line sensor SNL2 may be measured to be greater than itactually is. As a result, since the capacitance of a capacitor isproportional to the distance between the capacitor and a conductiveobject, the capacitance of the line sensing capacitor CF_L may bemeasured by the second line sensor SNL2 to be greater than the actualcapacitance of the line sensing capacitor CF_L.

On the other hand, in the case of sensing a fingerprint using thearea-driving fingerprint recognition method, a blur phenomenon betweenfingerprint ridges and valleys can be minimized by driving multiple areasensors, e.g., the first, second, third, fourth, and fifth area sensorsSNA1, SNA2, SNA3, SNA4, and SNA5, at the same time. For example, inresponse to a scan signal provided to the third area sensor SNA3, threeemission signals may be simultaneously provided to the second, third,and fourth area sensors SNA2, SNA3, and SNA4. Accordingly, the thirdarea sensor SNA3 can measure the capacitance of an area sensingcapacitor CF_A without being affected by any blur phenomenon.

In other words, the capacitance of the area sensing capacitor CF_A canbe measured more precisely than the capacitance of the line sensingcapacitor CF_L even when the same fingerprint ridge is sensed.

FIG. 6 is a waveform diagram showing emission clock signals and scanclock signals according to an exemplary embodiment of the presentinventive concept.

Referring to FIGS. 1 and 6, the timing controller 300 provides theemission control signal ECS and the scan control signal SCS to theemission driving unit 220 and the scan driving unit 210, respectively.Each of the emission control signal ECS and the scan control signal SCSincludes various control signals. For example, the emission controlsignal ECS includes first and second emission clock signals EM_CLK1 andEM_CLK2, and the scan control signal SCS includes first and second scanclock signals CLK1 and CLK2. The first and second emission clock signalsEM_CLK1 and EM_CLK2 and the first and second scan clock signals CLK1 andCLK2 may be provided by the timing controller 300 to drive the emissiondriving unit 220 and the scan driving unit 210. The first and secondemission clock signals EM_CLK1 and EM_CLK2 and the first and second scanclock signals CLK1 and CLK2 may be modulated into predeterminedfrequencies during a predetermined period of time.

The first and second emission clock signals EM_CLK1 and EM_CLK2 mayswing between a first gate-low voltage VGL and a first gate-high voltageVGH in first and second periods t1 and t2. In addition, the first andsecond scan clock signals CLK1 and CLK2 may swing between the firstgate-low voltage VGL and the first gate-high voltage VGH in the firstand second periods t1 and t2.

In the first period t1, the first emission clock signal EM_CLK1 mayquickly swing between the first gate-low voltage VGL and a secondgate-low voltage VGL′. In other words, in the first period t1, the firstemission clock signal EM_CLK1 may be modulated into a high frequency. Inthe first period t1, the second emission clock signal EM_CLK2 may havethe first gate-high voltage VGH.

In addition, in the first period t1, the first scan clock signal CLK1may have the first gate-low voltage VGL. In the first period t1, pulsesthat quickly swing between the first gate-high voltage VGH and a secondgate-high voltage VGH′ may be generated in the second scan clock signalCLK2. In other words, in the first period t1, the second scan clocksignal CLK2, like the first emission clock signal EM_CLK1, may bemodulated into a high frequency. However, the second scan clock signalCLK2 may only have the high frequency for a portion of the first periodt1. The pulses of the first emission clock signal EM_CLK1 may overlapwith the pulses of the second scan clock signal CLK2 or may be generatedearlier than, and disappear later than, the pulses of the second scanclock signal CLK2.

In the second period t2, the first emission clock signal EM_CLK1 mayhave the first gate-high voltage VGH. In the second period t2, thesecond emission clock signal EM_CLK2 may quickly swing between the firstgate-low voltage VGL and the second gate-low voltage VGL′. In otherwords, in the second period t2, the second emission clock signalEM_CLK2, like the first emission clock signal EM_CLK1 during the firstperiod t1, may be modulated into a high frequency.

In addition, in the second period t2, pulses that quickly swing betweenthe first gate-high voltage VGH and the second gate-high voltage VGH′may be generated in the first scan clock signal CLK1. In other words, inthe second period t2, the first scan clock signal CLK1, like the secondemission clock signal EM_CLK2, may be modulated into a high frequency.The second scan clock signal CLK2 may have the first gate-low voltageVGL. The pulses of the second emission clock signal EM_CLK2 may overlapwith the pulses of the first scan clock signal CLK1 or may be generatedearlier than, and disappear later than, the pulses of the first scanclock signal CLK1. This is so because the first scan clock signal CLK1may only have the high frequency for a portion of the second period t2.

As mentioned above, the first and second emission clock signals EM_CLK1and EM_CLK2 and the first and second scan clock signals CLK1 and CLK2may be signals modulated into predetermined frequencies, e.g., highfrequencies. The first and second emission clock signals EM_CLK1 andEM_CLK2 and the first and second scan clock signals CLK1 and CLK2 mayhave two voltages during a period when they are modulated into highfrequencies. In other words, the first and second emission clock signalsEM_CLK1 and EM_CLK2 and the first and second scan clock signals CLK1 andCLK2 may be “2-frequency, 3-level” signals. For example, the firstemission clock signal EM_CLK1 may have the first gate-low voltage VGLand the second gate-low voltage VGL′ in the first period t1 and may havethe first gate-high voltage VGH, which is different from the firstgate-low voltage VGL and the second gate-low voltage VGL′, in the secondperiod t2. By applying the first and second emission clock signalsEM_CLK1 and EM_CLK2 and the first and second scan clock signals CLK1 andCLK2, which are modulated into high frequencies, to the scan drivingunit 210 and the emission driving unit 220, noise that is generated whendriving the scan driving unit 210 and the emission driving unit 220 canbe reduced as compared to when unmodulated clock signals are applied tothe scan driving unit 210 and the emission driving unit 220.

The waveforms of the first and second emission clock signals EM_CLK1 andEM_CLK2 and the first and second scan clock signals CLK1 and CLK2 duringthe first and second periods t1 and t2 may be repeated over periodssubsequent to the second period t2. Therefore, detailed descriptions ofthe waveforms of the first and second emission clock signals EM_CLK1 andEM_CLK2 and the first and second scan clock signals CLK1 and CLK2 in theperiods subsequent to the second period t2 will be omitted.

FIG. 7 is a block diagram illustrating signal flows in the fingerprintrecognition device according to an exemplary embodiment of the presentinventive concept. Signals generated by the timing controller 300 andprovided to the emission driving unit 220 and the scan driving unit 210to drive the fingerprint recognition device 200 will hereinafter bedescribed with reference to FIG. 7.

Referring to FIGS. 1 and 7, the timing controller 300 may generate theemission control signal ECS, the scan control signal SCS, a mode signal“mode”, and an enable signal EN and may provide the emission controlsignal ECS, the scan control signal SCS, the mode signal “mode”, and theenable signal EN to the emission driving unit 220 and the scan drivingunit 210.

The mode signal “mode” may be a signal for distinguishing a touch modefrom a fingerprint recognition mode. When the mode signal “mode” is on,the fingerprint recognition device 200 may operate in the touch mode.The touch mode is a mode for sensing touch input generated by the userand calculating the coordinates of the touch input. When the mode signal“mode” is off, the fingerprint recognition device 200 may operate in thefingerprint recognition mode. The fingerprint recognition mode may be amode for sensing a fingerprint from the user and acquiring an image ofthe fingerprint. The mode signal “mode” may be controlled by the timingcontroller 300.

The enable signal EN may be a signal for driving the emission drivingunit 220 and the scan driving unit 210. The emission driving unit 220and the scan driving unit 210 may be driven only when the enable signalEN is on. In other words, when the enable signal EN is turned off froman on state, the emission driving unit 220 and the scan driving unit 210stop operating.

The emission control signal ECS may include the first initiation signalEM_FLM, the first emission clock signal EM_CLK1, and the second emissionclock signal EM_CLK2.

In response to the first initiation signal EM_FLM, which is a signal forinitiating the operation of the emission driving unit 220, applied tothe emission driving unit 220, the emission driving unit 220 maygenerate an emission signal VI, which is for driving the sensors SN ofthe sensing panel 205, and may provide the emission signal VI to thesensors SN. First initiation signal lines for providing the firstinitiation signal EM_FLM may be provided to correspond to the rows ofsensor blocks SB.

The first and second emission clock signals EM_CLK1 and EM_CLK2, whichare signals for driving the emission driving unit 220, may be signalsmodulated into predetermined frequencies, as mentioned above withreference to FIG. 6.

The scan control signal SCS may include the second initiation signalFLM, the first scan clock signal CLK1, and the second scan clock signalCLK2.

In response to the second initiation signal FLM, which is a signal forinitiating the operation of the scan driving unit 210, applied to thescan driving unit 210, the scan driving unit 210 may generate a scansignal SC for sensing measurement data from the sensors SN and mayprovide the scan signal SC to the sensors SN. Second initiation signallines for providing the second initiation signal FLM may be provided tocorrespond to the rows of sensor blocks SB.

The first and second scan clock signals CLK1 and CLK2, which are signalsfor driving the scan driving unit 210, may be signals modulated intopredetermined frequencies, as mentioned above with reference to FIG. 6.The first and second scan clock signals CLK1 and CLK2 may be applied tothe emission driving unit 220 and may then be transmitted from theemission driving unit 220 to the scan driving unit 210, as illustratedin FIG. 7, but the present inventive concept is not limited thereto.Alternatively, the first and second scan clock signals CLK1 and CLK2 maybe directly applied to the scan driving unit 210 from the timingcontroller 300.

The first emission clock signal EM_CLK1, the second emission clocksignal EM_CLK2, the first scan clock signal CLK1, the second scan clocksignal CLK2, the mode signal “mode”, and the enable signal EN may begenerated by a signal generator 310 of the timing controller 300 and maybe provided to the emission driving unit 220 and the scan driving unit210.

The first and second initiation signals EM_FLM and FLM may be generatedby an initiation signal generator 320 of the timing controller 300 andmay be applied to the emission driving unit 220 and the scan drivingunit 210, but the present inventive concept is not limited thereto.Alternatively, the timing controller 300 may output the addresses of thefirst and second initiation signals EM_FLM and FLM, and the initiationsignal generator 320, which is disposed on the outside of the timingcontroller 300, may generate the first and second initiation signalsEM_FLM and FLM. For example, in a case where the fingerprint recognitiondevice 200 includes 32 rows of sensing blocks SB, the timing controller300 may generate 5-bit signals and may transmit the 5-bit signals to theinitiation signal generator 320, which is disposed on the outside of thetiming controller 300. The 5-bit signals may be used to generate theaddresses of each of the 32 rows of sensing blocks SB. In other words,the initiation signal generator 320 may generate the first and secondinitiation signals EM_FLM and FLM based on 5-bit addresses provided bythe timing controller 300 and may then provide the first and secondinitiation signals EM_FLM and FLM to the emission driving unit 220 andthe scan driving unit 210.

The emission driving unit 220 may be configured to be driven insuccession. As mentioned above, the emission driving unit 220 maygenerate a carry signal and may thus be able to be driven in succession.The emission driving unit 220 may terminate its operation by turning offthe enable signal EN. In short, the operation of the emission drivingunit 220 may be initiated by the first initiation signal EM_FLM and maybe terminated by the enable signal EM.

The scan driving unit 210 may be divided into blocks to correspond tothe rows of sensing blocks SB. For example, an N-th row scan drivercorresponding to an N-th row sensing block SB[N,1] provides a last scansignal SC[25], but may not generate any carry signal. In other words,even if the N-th row scan driver is driven, an (N+1)-th row scan drivermay not be driven. The operation of each of the scan drivers of the scandriving unit 210 may be initiated only by the second initiation signalFLM.

To realize the area-driving fingerprint recognition method describedabove with reference to FIGS. 5A and 5B, the emission driving unit 220may be driven in a wider range than the scan driving unit 210. Forexample, in a case where 25 scan signals, e.g., N-th row first throughtwenty fifth scan signals SC[1] through SC[25], are applied to thesensing block SB[N,1], an (N−1)-th row emission driver may be driven inresponse to the N-th row first scan signal SC[1] and may provideemission signals VI[−1] and VI[0]. In addition, an N-th row emissiondriver may be driven and may provide emission signals VI[1], VI[2], andVI[3]. In other words, for the N-th row first scan signal SC[1], fiveemission signals, e.g., emission signals VI[−1], VI[0], VI[1], VI[2] andVI[3], may be generated, thereby realizing the area-driving fingerprintrecognition method. Similarly, for the N-th row second scan signalSC[2], the emission driving unit 220 may provide five emission signalsVI[0], VI[1], VI[2], VI[3], and VI[4]. Finally, in response to the N-throw twenty fifth scan signal SC[25], the emission driving unit 220 mayprovide five emission signals, e.g., an N-th row twenty third emissionsignal VI[23], an N-th row twenty fourth emission signal VI[24], an N-throw twenty fifth emission signal VI[25], an (N+1)-th row first emissionsignal VI[26], and an (N+1)-th row second emission signal VI[27].

Accordingly, in the case of applying five emission signals VI for eachscan signal SC and providing the scan signal SC to a total of 25 scanlines, the emission signals VI may be provided to a total of 29 emissionlines. By driving the emission driving unit 220 in a wider range thanthe scan driving unit 210, the area-driving fingerprint recognitionmethod can be realized, and a blur phenomenon that may occur at bothends of the scan driving unit 210 can be prevented.

FIG. 8 is a flowchart illustrating the operation of the fingerprintrecognition device according to an exemplary embodiment of the presentinventive concept. A fingerprint/touch sensing method of the displaydevice 10 including the fingerprint recognition device 200 willhereinafter be described with reference to FIGS. 1, 7, and 8. When anarbitrary signal is on, it means that the arbitrary signal has agate-high voltage. When the arbitrary signal is off, it means that thearbitrary signal has a gate-low voltage. When the arbitrary signal isturned on, it means that the arbitrary signal is turned on from an offstate. When the arbitrary signal is turned off, it means that thearbitrary signal is turned off from an on state.

Referring to FIGS. 1, 7, and 8, the main processor of the display device10 determines whether touch input from the user has been generated onthe display panel 100 (S100). In response to a determination being madethat the touch input has been generated by the user, the timingcontroller 300 determines whether the mode signal “mode” is on (S200).

The fingerprint recognition device 200 may be driven in the touch modeor the fingerprint recognition mode depending on whether the mode signal“mode” is on or off. When the mode signal “mode” is off, the fingerprintrecognition device 200 is driven in the fingerprint recognition mode(S300). When the mode signal “mode” is on, the fingerprint recognitiondevice 200 is driven in the touch mode (S400). In other words, thefingerprint recognition mode and the touch mode can be realized at thesame time by a single fingerprint recognition device 200.

The operation of the fingerprint recognition device 200 in thefingerprint recognition mode will hereinafter be described. Thefingerprint recognition mode may encompass a series of driving processesthat will hereinafter be described. If the mode signal “mode” is offwhen touch input is generated by the user, the timing controller 300 mayturn on the enable signal EN (S310). The enable signal EN may be asignal for driving the emission driving unit 220 and the scan drivingunit 210. In other words, in response to the enable signal EN beingturned on, the emission driving unit 220 and the scan driving unit 210may start operating.

Thereafter, the timing controller 300 may provide a first initiationsignal EM_FLM to the emission driving unit 220 (S320). The firstinitiation signal EM_FLM may be provided to the emission driving unit220, which corresponds to each of the rows of sensing blocks SB, via thefirst initialization signal lines, which are provided for the rows ofsensing blocks SB. The first initiation signal EM_FLM may initiate theoperation of the emission driving unit 220. For example, the firstinitiation signal EM_FLM may be provided to an emission drivercorresponding to a row including a sensing block SB corresponding to thelocation of the touch input from the user. To realize the area-drivingfingerprint recognition method described above with reference to FIGS.5A and 5B, the first initiation signal EM_FLM may be provided more thanonce. For example, the first initiation signal EM_FLM may besequentially provided five times.

The emission driving unit 220 may provide an emission signal VI tosensors SN (S330). The emission signal VI may be provided in the samemanner as the first initiation signal EM_FLM. In other words, theemission signal VI may be sequentially transmitted. For example, if thefirst initiation signal EM_FLM is sequentially provided five times, theemission signal VI may also be sequentially provided five times. Theemission driving unit 220 may sequentially provide the emission signalVI to sensors SN included in the sensing block SB corresponding to thelocation of the touch input from the user by generating a carry signal.The emission driving unit 220 may transmit the carry signal to anemission driver corresponding to a row subsequent to the row includingthe sensing block SB corresponding to the location of the touch inputfrom the user. Then, the emission driver receiving the carry signal maysequentially provide the emission signal VI to sensors SN.

After the generation of the first initiation signal EM_FLM and theemission signal VI, the timing controller 300 may provide a secondinitiation signal FLM to the scan driving unit 210 (S340). The secondinitiation signal FLM may be provided to the scan driving unit 210,which corresponds to each of the rows of sensing blocks SB, via thesecond initiation signal lines, which are provided for the rows of thesensing blocks SB. For example, the second initiation signal FLM may beprovided to a scan driver corresponding to the row including the sensingblock SB corresponding to the location of the touch input from the user.

The scan driving unit 210 may sequentially provide a scan signal SC tosensors SN (S350). The scan signal SC may be provided in the same manneras the second initiation signal FLM. The scan driving unit 210 may startoperating in response to the second initiation signal FLM. After thegeneration of the scan signal SC, the scan driving unit 210 maysequentially provide the scan signal SC to the sensors SN included inthe sensing block SB corresponding to the location of the touch inputfrom the user by generating a carry signal. The carry signal may not betransmitted between scan drivers corresponding to different rows ofsensing blocks SB. Accordingly, the scan driving unit 210 may stopoperating once its operation for a single sensing block SB is complete.The emission signal VI may be provided to sensors SN ahead of the scansignal SC. Sensors SN may receive the scan signal SC and may thus sensefingerprint information.

After S350, the timing controller 300 may turn off the enable signal EN(S500). In response to the enable signal EN being turned off, theoperations of the emission driving unit 220 and the scan driving unit210 may all be terminated. As mentioned above, the scan drivers of thescan driving unit 210 do not generate a carry signal for theirrespective subsequent scan drivers. On the other hand, since theemission drivers of the emission driving unit 220 generate a carrysignal for their subsequent emission drivers, the operation of theemission driving unit 220 may be terminated by turning off the enablesignal EN. The enable signal EN may be turned off when all emissionsignals for fingerprint recognition are provided.

The operation of the fingerprint recognition device 200 in the touchrecognition mode will hereinafter be described. The touch recognitionmode may encompass a series of driving processes that will hereinafterbe described. If the mode signal “mode” is on when the touch input isgenerated by the user, the fingerprint recognition device 200 may bedriven in the touch mode (S400). In the touch mode, the timingcontroller 300 may turn on the enable signal EN (S410).

Thereafter, the timing controller 300 may transmit the first and secondinitiation signals EM_FLM and FLM to the emission driving unit 220 andthe scan driving unit 210 at the same time (S420). In the touch mode,the first and second initiation signals EM_FLM and FLM may betransmitted to a first row emission driver and a first row scan driver.Once the driving of the first row emission driver and the first row scandriver in the touch mode is complete, the first and second initiationsignals EM_FLM and FLM may be sequentially transmitted to other emissiondrivers and other scan drivers so that all of the emission drivers andall of the scan drivers can receive the first and second initiationsignals EM_FLM and FLM. For example, the first and second initiationsignals EM_FLM and FLM may be transmitted to a second row emissiondriver and a second row scan driver, and so forth.

In response to the first and second initiation signals EM_FLM and FLM,the emission driving unit 220 and the scan driving unit 210 may transmitthe emission signal VI and the scan signal SC at the same time (S430).In the fingerprint recognition mode, the emission signal VI and the scansignal SC are sequentially provided to the sensors SN included in eachof the sensing blocks SB, but here in the touch mode, the emissionsignal VI and the scan signal SC may be provided to all the sensors SNin each of the sensing blocks SB at the same time. In other words, theamount of time required for sensing can be reduced by simultaneouslydriving all of the sensors SN in each of the sensing blocks SB.

After S430, the timing controller 300 may turn off the enable signal EN(S500). In response to the enable signal EN being turned off, theoperations of the emission driving unit 220 and the scan driving unit210 may all be terminated.

FIG. 9 is a timing diagram showing signals output by the timingcontroller and the sensing driver of the fingerprint recognition deviceaccording to an exemplary embodiment of the present inventive concept inthe fingerprint recognition mode. FIG. 10 is a timing diagram showingsignals output by the timing controller and the sensing driver of thefingerprint recognition device according to an exemplary embodiment ofthe present inventive concept when the fingerprint recognition mode iscomplete.

For example, FIGS. 9 and 10 are timing diagrams for a case where thefingerprint recognition device is driven in the fingerprint recognitionmode with the mode signal “mode” off. Referring to FIGS. 9 and 10, aminus first row refers to the second previous row from a first row, anda zeroth row refers to the first previous row from the first row. Inother words, the row next to the minus first row is the zeroth row, andthe row next to the zeroth row is the first row.

An operation performed on a single sensing block SB in the fingerprintrecognition mode will hereinafter be described with reference to FIGS. 1through 8. It is assumed that each sensing block SB includes a total of25 rows of sensors SN, and that the fingerprint recognition device 200includes 25 emission lines and 25 scan lines corresponding to the 25rows of sensors SN.

Each signal may swing between a gate-high voltage and a gate-lowvoltage. When each signal is on, it may mean that each signal has thegate-high voltage. When each signal is off, it may mean that each signalhas the gate-low voltage. When each signal is turned on, it may meanthat each signal is converted from the gate-low voltage to the gate-highvoltage. When each signal is turned off, it ma mean that each signal isconverted from the gate-high voltage to the gate-low voltage.

As mentioned above with reference to FIG. 6, the first and secondemission clock signals EM_CLK1 and EM_CLK2 and the first and second scanclock signals CLK1 and CLK2 may be signals modulated into highfrequencies. Since the first and second emission clock signals EM_CLK1and EM_CLK2 and the first and second scan clock signals CLK1 and CLK2are for driving the emission driving unit 220 and the scan driving unit210, an emission signal VI and a scan signal SC may also be signalsmodulated into high frequencies. Gray shaded areas in FIGS. 9 and 10indicate sections in which signals are modulated into high frequencies.An example of a gray shaded area corresponds to the low point of thefirst emission clock signal EM_CLK1 in period ta1. Another example ofthe gray shaded area corresponds to the high point of the second scanclock signal CLK2 in the period ta1.

In a first initiation period ta1 when the fingerprint recognition modeis initiated, the timing controller 300 may turn on the enable signalEN. In other words, the enable signal EN goes from high to low. Inresponse to the enable signal EN being turned on, the emission drivingunit 220 and the scan driving unit 210 may start operating. As theenable signal EN is turned on, the timing controller 300 may provide afirst initiation signal EM_FLM to the emission driving unit 220. Thefirst initiation signal EM_FLM may be sequentially provided more thanonce to realize the area-driving fingerprint recognition method. FIG. 9shows an example in which the first initiation signal EM_FLM issequentially provided five times over a period from the first initiationperiod ta1 to a fifth initiation period ta5.

In a second initiation period ta2, the timing controller 300 may providethe first initiation signal EM_FLM to the emission driving unit 220. Inresponse to the first initiation signal EM_FLM being provided in thefirst initiation period ta1, the emission driving unit 220 may providean emission signal VI[−1] to the sensors SN of the sensing panel 205.For example, the emission driving unit 220 may provide the emissionsignal VI[−1] to a minus first row of sensors SN to perform thearea-driving fingerprint recognition method on a first row of sensorsSN. More specifically, a minus first row emission driver may generatethe emission signal VI[−1] and may transmit a carry signal to a zerothrow emission driver.

In a third initiation period ta3, the timing controller 300 may providethe first initiation signal EM_FLM to the emission driving unit 220. Theemission driving unit 220 may transmit the emission signal VI[−1] and anemission signal VI[0] to the minus first row of sensors SN and a zerothrow of sensors SN, respectively. This can be seen, for example, by theemission signal VI[−1] and the emission signal VI[0] going low in thethird initiation period ta3.

In a fourth initiation period ta4, the timing controller 300 may providethe first initiation signal EM_FLM to the emission driving unit 220, andthe emission driving unit 220 may provide the emission signal VI[−1],the emission signal VI[0], and an emission signal VI[1] to the minusfirst row of sensors SN, the zeroth row of sensors SN, and a first rowof sensors SN, respectively. This can be seen, for example, by theemission signal VI[−1], the emission signal VI[0] and the emissionsignal VI[1] going low in the fourth initiation period ta4.

In the fifth initiation period ta5, the timing controller 300 mayprovide the first initiation signal EM_FLM to the emission driving unit220, and the emission driving unit 220 may provide the emission signalVI[−1], the emission signal VI[0], the emission signal VI[1], and anemission signal VI[2] to the minus first row of sensors SN, the zerothrow of sensors SN, the first row of sensors SN, and a second row ofsensors SN, respectively. In addition, the timing controller 300 mayprovide a second initiation signal FLM to the scan driving unit 210.This occurs when, for example, the second initiation signal FLM goeshigh in the fifth initiation period ta5.

In a sixth initiation period ta6, the emission driving unit 220 mayprovide the emission signal VI[−1], the emission signal VI[0], theemission signal VI[1], the emission signal VI[2], and an emission signalVI[3] to the minus first row of sensors SN, the zeroth row of sensorsSN, the first row of sensors SN, the second row of sensors SN, and athird row of sensors SN, respectively, and the scan driving unit 210 mayprovide a scan signal SC[1] to the first row of sensors SN. This occurswhen, for example, the scan signal SC[1] goes high in the sixthinitiation period ta6. In other words, the fingerprint recognitiondevice 200 may perform fingerprint recognition on the first row ofsensors SN in the area-driving fingerprint recognition method.

In a seventh initiation period ta7, the emission driving unit 220 mayprovide the emission signal VI[0], the emission signal VI[1], theemission signal VI[2], the emission signal VI[3], and an emission signalVI[4] to the zeroth row of sensors SN, the first row of sensors SN, thesecond row of sensors SN, the third row of sensors SN, and a fourth rowof sensors SN, respectively, and the scan driving unit 210 may providethe scan signal SC[2] to the second row of sensors SN. This occurs when,for example, the scan signal SC[2] goes high in the seventh initiationperiod ta7.

In an eighth initiation period ta8, the emission driving unit 220 mayprovide the emission signal VI[1], the emission signal VI[2], theemission signal VI[3], the emission signal VI[4], and an emission signalVI[5] to the first row of sensors SN, the second row of sensors SN, thethird row of sensors SN, the fourth row of sensors SN, and a fifth rowof sensors SN, respectively. The emission signal VI[5] is notillustrated in FIG. 9, but may be provided in the same manner as theother emission signals.

Similarly, in ninth, tenth and eleventh initiation periods ta9, ta10 andta11, five emission signals VI may be provided for a single scan signalSC so that the area-driving fingerprint recognition method can beperformed. In addition, even after the eleventh initiation period ta11,the fingerprint recognition mode can be continued in the same manner asdescribed above.

FIG. 10 is a timing diagram illustrating an operation performed on rowsof sensors SN at or near the end of a sensing block SB.

Referring to FIG. 10, in a first termination period tb1, the emissiondriving unit 220 may provide emission signals to twenty first throughtwenty fifth rows of sensors SN, and the scan driving unit 210 mayprovide a scan signal SC[23] to the twenty third row of sensors SN.

In a second termination period tb2, the emission driving unit 220 mayprovide an emission signal VI[26] to a twenty sixth row of sensors SN toperform the area-driving fingerprint recognition method, and the scandriving unit 210 may provide a scan signal SC[24] to the twenty fourthrow of sensors SN.

In a third termination period tb3, the emission driving unit 220 mayprovide the emission signal VI[26] and an emission signal VI[27] to thetwenty sixth row of sensors SN and a twenty seventh row of sensors SN,respectively, to perform the area-driving fingerprint recognitionmethod, and the scan driving unit 210 may provide a scan signal SC[25]to the twenty fifth row of sensors SN. In other words, the emissiondriving unit 220 may provide emission signals to the twenty thirdthrough twenty seventh rows of sensors SN, and the scan driving unit 210may provide the scan signal SC[25] to the twenty fifth row of sensorsSN. Thereafter, the timing controller 300 may turn off the enable signalEN to terminate the fingerprint recognition mode.

In a fourth termination period tb4, since the enable signal EN is off(e.g., low), the operations of the emission driving unit 220 and thescan driving unit 210 may be terminated.

FIG. 11 is a timing diagram showing signals output by the timingcontroller and the sensing driver of the fingerprint recognition deviceaccording to an exemplary embodiment of the present inventive conceptwhen the touch mode is driven and when the touch mode is complete.

In a first touch period tc1 when the touch mode is initiated, the timingcontroller 300 may turn on the enable signal EN. As the enable signal ENis turned on, the timing controller 300 may provide may provide thefirst initiation signal EM_FLM and the second initiation signal FLM tothe emission driving unit 220 and the scan driving unit 210.

In a second touch period tc2, the emission driving unit 220 and the scandriving unit 210 may provide the emission signals VI[−1] through VI[27]and the scan signals SC[1] through SC[25] to all the sensors SN at thesame time. Thereafter, the timing controller 300 may turn off the enablesignal EN to terminate the touch mode.

In a third touch period tc3, since the enable signal EN is off, theoperations of the emission driving unit 220 and the scan driving unit210 may be terminated.

In the touch mode, all the sensors SN may be driven to sense touchinput. Alternatively, only some of the sensors SN may be driven. Inother words, in the touch mode, touch input can be sensed by applying anemission signal VI and a scan signal SC to only some of the sensors SN.For example, touch input can be sensed by driving only the odd-numberedrows of sensors SN or the first through fifteenth rows of sensors SN. Inthis example, the power consumption of the fingerprint recognitiondevice 200 can be reduced as compared to the case of sensing touch inputby driving all the sensors SN.

FIG. 12 is a circuit diagram of a capacitive fingerprint sensoraccording to another exemplary embodiment of the present inventiveconcept. The exemplary embodiment of FIG. 12 differs from the exemplaryembodiment of FIG. 4 in that a fingerprint sensor includes P-typeMOSFETs. The exemplary embodiment of FIG. 12 will hereinafter bedescribed, focusing mainly on the difference with the exemplaryembodiment of FIG. 4.

Referring to FIG. 12, a sensor SN_1 may include first, second, and thirdtransistors T1′, T2′, and T3′. The first, second, and third transistorsT1′, T2′, and T3′ may be P-type MOSFETs. Thus, in response to agate-high voltage being applied to the gate electrodes of the first,second, and third transistors T1′, T2′, and T3′, the first, second, andthird transistors T1′, T2′, and T3′ may be turned off, and in responseto a gate-low voltage being applied to the gate electrodes of the first,second, and third transistors T1′, T2′, and T3′, the first, second, andthird transistors T1′, T2′, and T3′ may be turned on. Accordingly, thephase of a scan signal SC′ applied to a scan line SL′ connected to thegate electrode of the second transistor T2′ may be opposite to the phaseof the scan signal SC of FIG. 4, and the phase of an emission signalVIN′ applied to an emission line EL′ connected to the gate electrode ofthe third transistor T3′ may be opposite to the phase of the emissionsignal VI of FIG. 4.

The voltage applied to a first node N1′ may vary depending on thecapacitance of a sensing capacitor CF′ generated by touch input from theuser. Accordingly, the voltage applied to the gate electrode of thefirst transistor T1′ and a drain-source current Ids' of the firsttransistor T1′ may also vary. A read-out line RL′ can sense thesevariations and can thus recognize a fingerprint.

A fingerprint recognition device according to another exemplaryembodiment of the present inventive concept will hereinafter bedescribed. In FIGS. 1 through 16, like reference numerals may indicatelike elements, and thus, detailed descriptions thereof will be omitted.The fingerprint recognition device according to another exemplaryembodiment of the present inventive concept will hereinafter bedescribed, focusing mainly on differences with the fingerprintrecognition device 200.

FIG. 13 is a circuit diagram of an optical fingerprint sensor accordingto another exemplary embodiment of the present inventive concept. FIG.14 is a block diagram of a display device including the opticalfingerprint sensor of FIG. 13. FIG. 15 is a block diagram of afingerprint recognition device including the optical fingerprint sensorof FIG. 13.

The exemplary embodiment of FIGS. 13 through 15 differs from theexemplary embodiment of FIGS. 1 through 4 in that optical fingerprintsensors are used. The exemplary embodiment of FIGS. 13 through 15 willhereinafter be described, focusing mainly on the difference with theexemplary embodiment of FIGS. 1 through 4.

FIG. 13 is a circuit diagram of an optical fingerprint sensor. Referringto FIG. 13, an optical sensor SN_2 may include a photoelectricconversion element PD.

The optical sensor SN_2 may be an optical fingerprint sensor capable ofrecognizing a fingerprint by sensing light reflected from fingerprintridges and valleys with an image sensor. The optical sensor SN_2 mayinclude the photoelectric conversion element PD. For example, thephotoelectric conversion element PD may be a photodiode, aphototransistor, a photogate, or a pinned photodiode. In the descriptionthat follows, it is assumed that the photoelectric conversion element PDis a photodiode.

The optical sensor SN_2 may have a “1 transistor-1 diode” structureincluding a single transistor PT1 and the photoelectric conversionelement PD.

The optical sensor SN_2 senses light reflected by a different part of afinger and generates an electrical signal corresponding to the sensedlight. The optical sensor SN_2 may generate an electrical signalcorresponding to light reflected from a fingerprint ridge or afingerprint valley. The amount of light sensed by the photoelectricconversion element PD may vary depending on the shape of a fingerprint,and electrical signals having different levels may be generateddepending on the amount of light sensed by the photoelectric conversionelement PD.

A drain-source current that passes through the channel of the transistorPT1 may vary depending on an electrical signal generated by the opticalsensor SN_2. In response to a scan signal being applied via a scan linePSL[N], a fingerprint sensing signal SS may be scanned via a read-outline RL. In other words, an electrical signal from the optical sensorSN_2 may include contrast information or image information. Theelectrical signal may be processed to determine whether a part of afinger corresponding to the optical sensor SN_2 is a fingerprint ridgeor a fingerprint valley, and a fingerprint image may be configured bycombining the result of the determination. In FIG. 13, light sensed atthe photoelectric conversion element PD may be denoted by L, PSL[N−1]corresponds to a scan line and VB corresponds to a voltage line.

Referring to FIGS. 14 and 15, a display device 102 may include a displaypanel 100_2, a fingerprint recognition device 200_2, and a timingcontroller 300_2. The display panel 100_2 may include a plurality oftouch sensing units TU, and the fingerprint recognition device 200_2 mayinclude a plurality of optical fingerprint sensors SN_2.

The display panel 1002, like the display panel 100 of FIG. 1, mayinclude a plurality of pixels and may provide an image to the outside.The display panel 100_2 may be an OLED display panel including OLEDs. Inthe description that follows, it is assumed that the display panel 100_2is an OLED display panel, but the present inventive concept is notlimited thereto. Alternatively, the display panel 1002 may be an LCDpanel or an mLED display panel.

The display panel 100_2 may include a touch sensing member 105. Thetouch sensing member 105 may be continuously formed on the OLEDs of thedisplay panel 100_2. For example, the OLEDs may be disposed on thedisplay panel 100_2, and the touch sensing member 105 may becontinuously formed on a passivation layer for protecting the OLEDs.However, the present inventive concept is not limited to this example.In another example, the touch sensing member 105 may be formed on aseparate panel from the display panel 100_2.

The touch sensing member 105 may include a plurality of touch drivinglines TSL, e.g., touch driving lines TSL1 through TSLp (where p is apositive integer of 2 or greater), a plurality of touch sensing linesTRL, e.g., touch sensing lines TRL1 through TRLq (where q is a positiveinteger of 2 or greater), and a plurality of touch sensing units TU. Thetouch driving lines TSL may be disposed to intersect the touch sensinglines TRL.

The touch sensing units TU may have a multilayer structure and may senseexternal output in a capacitive manner. Each of the touch sensing unitsTU may include a first conductive layer, a second conductive layer, andan insulating layer. One of the first and second conductive layers maybe connected to one of the touch driving lines TSL and one of the touchsensing lines TRL, and the first and second conductive layers may beinsulated from each other by the insulating layer. In other words, eachof the touch sensing units TU may be connected to one of the touchdriving lines TSL and one of the touch sensing lines TRL. In response toa touch input, the capacitance between the first and second conductivelayers may vary, and such capacitance variations may be touch signalsTSS.

A touch driving circuit unit TSD may be connected to the touch drivinglines TSL and may sequentially provide touch driving voltages to thetouch sensing units TU. The touch driving circuit unit TSD may beconnected to the timing controller 300_2 and may receive touch drivingcontrol signals.

A touch sensing circuit unit TROC may be connected to the touch sensinglines TRL. The touch sensing circuit unit TROC may sequentially providethe touch signals TSS, received from the touch sensing units TU, to thetiming controller 300_2. The timing controller 300_2 may calculate thecoordinates of a touch input based on the touch signals TSS. The touchsensing circuit unit TROC may receive touch sensing control signals fromthe timing controller 300_2.

The fingerprint recognition device 2002 may include a sensing panel205_2, a scan driving unit 210_2, a read-out circuit unit 230, and thetiming controller 300_2.

The sensing panel 205_2 may be implemented as a semiconductor chip or asemiconductor package and may be attached to the bottom surface of thedisplay panel 100_2. The sensing panel 205_2 may be a semiconductorlayer with image sensors such as CMOS image sensors (CIS) orcharge-coupled devices (CCDs) formed thereon.

The sensing panel 205_2, which includes the optical fingerprint sensorsSN_2, detects a fingerprint of a finger that is placed in contact with,or adjacent to, the display panel 100_2. In a case where the displaypanel 100_2 is an OLED display panel and a fingerprint of a user isplaced on the display panel 100_2, light from the OLEDs of the displaypanel 100_2 may be transmitted to, and reflected from, the fingerprintof the user, and the reflected light may be transmitted to the sensingpanel 2052 through pin holes of the display panel 100_2.

For example, a plurality of scan lines, e.g., first through i-th scanlines SL1 through SLi (where i is a positive integer of 2 or greater), aplurality of read-out lines, e.g., read-out lines RL1 through RLj (wherej is a positive integer of 2 or greater), and the optical fingerprintsensors SN_2 may be disposed on the sensing panel 205_2. The scan linesSL1 through SLi may be disposed to intersect the read-out lines RL1through RLj. Each of the optical fingerprint sensors SN_2 of the sensingpanel 2052 may be connected to one of the scan lines SL1 through SLi andone of the read-out lines RL1 through RLj.

The scan driving unit 210_2 may be connected to the scan lines SL1through SLi and may provide a scan signal to the optical fingerprintsensors SN_2. The scan driving unit 210_2 may receive a scan controlsignal SCS from the timing controller 300_2. The scan control signal SCSmay include an initiation signal FLM and may control the scan drivingunit 210_2.

In response to a read-out control signal RCS being provided from thetiming controller 300_2, the read-out circuit unit 230 may sequentiallyprovide fingerprint sensing signals SS, received from the read-out linesRL1 through RLj, to the timing controller 300_2.

The fingerprint recognition device 2002, which includes the opticalfingerprint sensors SN_2, may not perform the area-driving fingerprintrecognition method described above with reference to FIGS. 5A and 5B. Inother words, the fingerprint recognition device 2002 may not include anemission driving unit for performing the area-driving fingerprintrecognition method. The fingerprint recognition device 200_2 may onlyinclude the scan driving unit 210_2 and may sense signals according tothe line-driving fingerprint recognition method.

FIG. 15 shows that the sensing panel 2052 is divided into a plurality ofsensing blocks SB. For convenience, only some of the scan lines SL1through SLi and only some of the read-out lines RL1 through RLj areillustrated in FIGS. 14 and 15.

The fingerprint recognition device 200_2, like the fingerprintrecognition device 200 of FIG. 2, may be divided into a plurality ofsensing blocks SB, e.g., sensing blocks SB[1,1] through SB[i,j]. Each ofthe sensing blocks SB may include multiple optical fingerprint sensorsSN_2, and the sensing blocks SB may be arranged on the sensing panel205_2 in rows and columns. Initiation signal lines may be disposed tocorrespond to the sensing blocks SB. The initiation signal lines maytransmit the initiation signal FLM, provided by the timing controller300_2, to the scan driving unit 210_2, which corresponds to the sensingblocks SB.

Each of the scan lines SL1 through SL1 and each of the read-out linesRL1 through RLj are illustrated as being single lines connected to oneof the sensing blocks SB, but may actually be groups of lines connectedto multiple optical fingerprint sensors SN_2 included in one of thesensing blocks SB.

The fingerprint recognition device 2002, which includes the opticalfingerprint sensors SN_2, may be driven in a fingerprint recognitionmode and in an average recognition mode. The fingerprint recognitionmode may be as described above with reference to FIGS. 9 and 10, and theaverage recognition mode may be similar to the driving method describedabove with reference to FIG. 11.

In the fingerprint recognition mode, the scan driving unit 210_2 mayreceive the initiation signal FLM from the timing controller 300_2. Thefingerprint recognition device 200_2 may include the initiation signallines corresponding to the sensing blocks SB. In other words, byproviding the initiation signal FLM only to a sensing block SB thatneeds to be sensed, fingerprint information can be sensed from just thesensing block SB that needs to be sensed.

As mentioned above, in response to a touch input being generated, thetouch sensing circuit unit TROC may receive the touch signals TSS fromthe touch sensing units TU and may provide the touch signals TSS to thetiming controller 300_2. The timing controller 300_2 may detect thetouch coordinates of the touch input based on the touch signals TSS andmay provide the initiation signal FLM only to a scan drivercorresponding to a row including a sensing block SB that corresponds tothe touch coordinates of the touch input. In other words, the timingcontroller 300_2 may selectively provide the initiation signal FLM onlyto a scan driver corresponding to the detected touch coordinates. Thescan driver to which the initiation signal FLM is provided maysequentially provide a scan signal to the optical fingerprint sensorsSN_2. The read-out circuit unit 230 may scan fingerprint sensing signalsSS via the read-out lines RL1 through RLj.

The fingerprint recognition device 200_2 may control the number ofsensing blocks SB that need to be sensed for fingerprint recognition viathe timing controller 300_2. In other words, the timing controller 300_2may provide the initiation signal FLM not only to the scan drivercorresponding to the detected touch coordinates, but also to scandrivers adjacent to the scan driver corresponding to the detected touchcoordinates.

For example, if each of the sensing blocks SB is 4 mm long in a verticaldirection, an 8-mm long fingerprint recognition area can be secured bydriving two rows of sensing blocks SB or a 12-mm long fingerprintrecognition area can be secured by driving three rows of sensing blocksSB.

The fingerprint recognition device 200_2, which includes the opticalfingerprint sensors SN_2, may be driven in the average recognition mode.In the average recognition mode, the fingerprint recognition device200_2 may be driven in a similar manner to that described above withreference to FIG. 11. In the average recognition mode, the timingcontroller 3002 may provide the initiation signal FLM to the scandrivers of the scan driving unit 210 at the same time. In response tothe initiation signal FLM being provided to the scan drivers of the scandriving unit 210 at the same time, all the optical fingerprint sensorsSN_2 included in each of the sensing blocks SB may be simultaneouslyprovided with a scan signal.

In the average recognition mode, the fingerprint recognition device2002, which includes the optical fingerprint sensors SN_2, can measurethe average amount of light provided to each of the sensing blocks SB,and the result of the measurement may be used to tune and adjust thedynamic range and the offset of the read-out circuit unit 230.Accordingly, the signal-to-noise ratio (SNR) of the fingerprintrecognition device 200_2 can be raised, and as a result, the reliabilityof the fingerprint recognition device 200_2 can be increased. Inaddition, in the case of using the fingerprint recognition device 200_2to perform liveness detection for anti-spoofing purposes, variations inthe amount of light sensed, rather than individual sensor information,needs to be monitored. Therefore, the fingerprint recognition device200_2 can quickly and precisely measure such variations using theaverage recognition mode. Moreover, in the case of using the fingerprintrecognition device 200_2 as an illumination sensor, the fingerprintrecognition device 200_2 can quickly and precisely measure the amount oflight using the average recognition mode.

FIG. 16 is a circuit diagram of an optical fingerprint sensor accordingto an exemplary embodiment of the present inventive concept.

An optical fingerprint sensor SN_3 of FIG. 16 differs from the opticalfingerprint sensor SN_2 of FIG. 13 in that it includes three transistorsPT2, PT3 and PT4 and a photoelectric conversion element PD. In otherwords, the optical fingerprint sensor SN_3 of FIG. 16 may have a “3transistors-1 diode” structure. The operation of the optical fingerprintsensor SN_3 of FIG. 16 is almost the same as the operation of theoptical fingerprint sensor SN_2 of FIG. 13, and thus, a detaileddescription thereof will be omitted. In FIG. 16, light sensed at thephotoelectric conversion element PD may be denoted by L, SL[N] andSL[N+1] correspond to scan lines, and VIN, VC and VPD correspond tovoltage lines.

While the present inventive concept has been particularly shown anddescribed with reference to exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and details may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims.

What is claimed is:
 1. A fingerprint recognition device, comprising: asensing panel including a plurality of sensing blocks, wherein each ofthe sensing blocks includes a plurality of sensors; a scan driving unitconfigured to provide a scan signal to the sensors; and a timingcontroller configured to provide a second initiation signal to the scandriving unit, wherein each of the sensors includes a reference capacitorand a sensing capacitor, the scan driving unit includes scan driversthat correspond to rows of the sensing blocks, in a fingerprintrecognition mode, the timing controller provides the second initiationsignal to a scan driver corresponding to a sensing block where a touchinput is generated, and in a touch mode, the timing controllersequentially provides the second initiation signal to the scan drivers.2. The fingerprint recognition device of claim 1, wherein the referencecapacitor has a fixed capacitance, and the sensing capacitor has avariable capacitance that varies depending on a distance to afingerprint.
 3. The fingerprint recognition device of claim 2, furthercomprising: an emission driving unit configured to receive a firstinitiation signal from the timing controller and provide an emissionsignal to the sensors.
 4. The fingerprint recognition device of claim 3,wherein in the touch mode, the timing controller provides an on-statemode signal to the scan driving unit, and in the fingerprint recognitionmode, the timing controller provides an off-state mode signal to thescan driving unit.
 5. The fingerprint recognition device of claim 4,wherein in the fingerprint recognition mode, the emission driving unitsequentially provides the emission signal to the sensors, and the scandriving unit sequentially provides the scan signal to the sensors. 6.The fingerprint recognition device of claim 5, wherein the firstinitiation signal is provided before the second initiation signal, andthe emission signal is provided before the scan signal.
 7. Thefingerprint recognition device of claim 6, wherein the first initiationsignal includes at least three consecutive pulses, and the secondinitiation signal is provided when a last pulse of the first initiationsignal is provided.
 8. The fingerprint recognition device of claim 4,wherein in the touch mode, the emission driving unit and the scandriving unit provide the emission signal and the scan signal to thesensors at the same time.
 9. The fingerprint recognition device of claim8, wherein the emission driving unit and the scan driving unit providethe emission signal and the scan signal only to some of the sensors. 10.The fingerprint recognition device of claim 3, wherein the timingcontroller provides first and second emission clock signals havingopposite phases with respect to each other to the scan driving unit andprovides first and second scan clock signals having opposite phases withrespect to each other to the scan driving unit, the first and secondemission clock signals include sections modulated into high frequencies,and the first and second scan clock signals include sections modulatedinto high frequencies.
 11. The fingerprint recognition device of claim3, wherein the timing controller provides an enable signal to theemission driving unit and the scan driving unit, and when the enablesignal is turned off, all operations of the emission driving unit andthe scan driving unit are terminated.
 12. A driving method of afingerprint recognition device comprising a sensing panel including aplurality of sensing blocks each including a plurality of sensors, anemission driving unit for providing an emission signal to the sensors, ascan driving unit for providing a scan signal to the sensors, and atiming controller for providing a first initiation signal to theemission driving unit and for providing a second initiation signal tothe scan driving unit, the driving method comprising: receiving a touchinput at the sensing panel; determining, by the timing controller,whether a mode signal is on or off; and driving the fingerprintrecognition device in a fingerprint recognition mode when the modesignal is off and driving the fingerprint recognition device in a touchmode when the mode signal is on.
 13. The driving method of claim 12,wherein the driving of the fingerprint recognition device in thefingerprint recognition mode, comprises sequentially providing, by thetiming controller, the first initiation signal to the emission drivingunit, sequentially providing, by the emission driving unit, the emissionsignal to the sensors, providing, by the timing controller, the secondinitiation signal to the scan driving unit, sequentially providing, bythe scan driving unit, the scan signal to the sensors, and turning off,by the timing controller, an enable signal, and the first and secondinitiation signals are provided to an emission driver and a scan driverboth corresponding to a row including a sensing block where the touchinput is generated.
 14. The driving method of claim 13, wherein thedriving of the fingerprint recognition device in the touch mode,comprises turning on, by the timing controller, the enable signal,providing, by the timing controller, the first and second initiationsignals to the scan driving unit and the emission driving unit at thesame time, providing, by the emission driving unit and the scan drivingunit, the emission signal and the scan signal to the sensors at the sametime, and turning off, by the timing controller, the enable signal, andthe first and second initiation signals are sequentially provided toemission drivers that correspond to rows of the sensing blocks and toscan drivers that correspond to the rows of the sensing blocks.